Fluid-compressor



'(No Model.)

J. REBSAMIEN.V

` Y y FLUID GOMPRESSOR. No. 500,720.

Patented July `4,- `1893.

UNITED STATES PATENT OEETCE.

JULIUS REBSAMEN, OF CHICAGO, ILLINOIS.

FLUID-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 500,720, dated July 4,1893.

Application led January 15, 1892. Serial No. 418,182. (No model.)

To @ZZ whom it may concern:

Be it known that I, JLIU `REBSAMEY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Improvernent in Fluid-Compressors, of whichthe following is a specification.

The object of myimprovement is to provide for avoiding clearance of thepistons in the cylinders of compressors of the class to which myinvention relates, thereby to overcome the loss of power incidental toclearance of the pistons particularly in air and gas compressors.

I have especially devised my improvement with relation to the compressorof a so-called ammonia ice or refrigerating machine, and thereforeintend the description, hereinafter contained, in the main to apply tothe use of my improvement in that particular connection, though it willbe understood as being equally and similarly operative in any connectionwith which it is adapted to be used, and that I do not intend to limitit in respect to any particular connection.

Generally stated, my improvement involves a hollow piston in andcontrollably communieating with its cylinder and containing asupplemental piston, the two pistons being relatively yielding underabnormal resistance, and a piston-rod connecting the pistons with thedriving-medium, whereby when the stroke `of the hollow piston hascarried it to a cylinder-head,anyckcessof the stroke that would tend toforce it beyond the cylinder-head will be taken up by the piston-yield.

In the accompanying drawings, Figure l is a broken longitudinalsectional view of a compressor having the piston itself constructed torender it yielding for my purpose; and Fig. 2 is a sectional view in thenature of a diagram, showing the relation of the piston to itsdriving-medium at the end of a stroke.

A is the cylinder shown as provided with bulging heads B and B', thoughthe heads might be flat or of still other form without departure from myinvention. Inlet-pipes r, r', and discharge-pipes q and q' for theammonia gas to be acted on, are connected with the heads, asrepresented, and are controlled,

in a usual manner, respectively, by inletvalves p and outlet-valves p.

The foregoing details belong to the particular compressor selected fordemonstrating my improvement, and may be modified or departed from invarious ways without affecting my invention.

Inside the cylinder A is a hollow piston C, suitably packed, and theheads 'n and n of which should conform to those of the cylinder, eachpiston-end containing a safety-valve m and a pressure-inlet valve Z.Inside the piston C is closely fitted and suitably packed a supplementalpiston C', containing checkvalves c' and t", the one opening into achamber 7e, formed between the forward ends of the hollow piston C andsupplemental piston C', and the other opening into a chamber la' formedbetween the rear ends thereof. The two chambers 7c and 7c are thusrendered intercommunicating.

D is the piston-rod connected with the supplemental piston C', passingthence through stuffing-boxes h and h, respectively `in the heads n andB, and connected at its rear end with a driver E, represented in thepresent instance, in Fig. 2, as a rotary shaft having a crank F, withwhich the rod D is connected by means of a pitman g. The connection ofthe supplemental piston with the piston C, while yielding under abnormalresistance, such as would be presented by impact of the piston against ahead of a cylinder, is adequately stiff to resist yielding under thestress of the work to which the supplemental piston C is applied indriving the piston C.

The back-stroke of the piston C draws gas into the cylinder A at itsforward end through the valve p, and compresses that previouslyadmitted, by the forward stroke of the piston into the rear end of thecylinder through the valve r', out through a valve p; and the forwardstroke of the piston obviously draws gas behind it into the cylinder anddischarges that in front of it through a valve p". The valves m and Zhave their controlling-springs set to resist any pressure lower thanthat at which the gas is to be compressed out of the cylinder, so thatgas at the same pressure is admitted into the interior of the piston Cas into the cylinder A; and the check-valves and e" convey the pressurefrom one of the chambers k la into the other when the supplementalpiston comes into play, as hereinafter described.

Reference to Fig. 2 will show that the piston C reaches, in its forwardstroke, the forward head B of the cylinder A before the crank F hasreached its dead-center line 1o with the piston-rod, and that, were thepiston unyielding, further turning of the crank to the point x wouldforce out the cylinder-head. The yielding nature of the piston, however,by the movable quality of its supplemental piston C against theresistance of the gas under pressure in the chamber 7c, enables it to bemoved forward against the cushion aorded by the gas in that chamber, thepressure against which forces it past the check-valve 2o t" into thechamber Zr; and that movement causes the supplemental piston to take up,as it were, the excess of the forward stroke, thereby insuring theavoidance of clearance of the piston without damage or even injuz 5rious strain to the cylinder. The same conditions present themselvesunder the back stroke of the piston C.

Other means than those described and illustrated may be employed, foreffecting my pur- 3o pose, as within the scope of my general statementof invention herein contained, provided such means involve theemployment of a hollow piston within and communicating with the cylinderand any means be provided for rendering the hollow piston and thesupplemental piston contained therein relatively yielding under abnormalpressure.

What I claim as new, and desire to secure by Letters Patent, isv 4o 1. na compressor, the combination with the cylinder and the pistoudriving-medium,

of a hollow piston in and controllably communicating with the cylinder,a supplemental piston confined in the hollow piston, the two pistonsbeing relatively yielding under abnormal pressure, and a piston-rodconnecting the pistons with the driving-medium, whereby, when the strokeof the hollow piston has carried it to a cylinder-head, any excess ofthe stroke that would tend to force it beyond 5o the cylinder-head willbe taken up by the piston-yield, substantially as described.

2. In a compressor, the combination with the cylinder and the pistondriving-medium, of a hollow piston in and controllably communicatingwith the cylinder, a supplemental piston yieldingly confined in thehollow piston, and a piston-rod connecting the supplemental piston withthe driving-medium and adjusted to continue the stroke of the piston- 6orod when the hollow piston has reached the end of its stroke,substantially as and for the purpose set forth.

3. In a compressor, the combination with the piston driving-medium of acylinder A' 65 having valve-controlled inlets fr, r and outlets q, q', ahollow piston C within the cylinder and provided with valves m and Z, asupplemental piston C yieldingly confined in the hollow piston andprovided with valves z', i', 7c and a piston-rod D connecting thesupple` mental piston with the driving-medium and adjusted to continuethe stroke of the supplemental piston when the hollow piston has reachedthe end of its stroke, substantially as and for ythe purpose set forth.

JULIUS REBSAMEN.

In presence of- M. J. FRosT, J. N. HANsoN.

